Interlocking corner construction for containers



April 1951 R. B. MELLER 2,550,582

INTERLOCKING CORNER CONSTRUCTION FOR CONTAINERS 9 Sheets-Sheet 1 Filed Aug. 14, 1945 REGINALD B. HELLER Maw worm;

April 24, 1951 R. B. MELLER 2,550,582

' INTERLOCKING CORNER CONSTRUCTION FOR CONTAINERS Filed Aug. 14, 1945 9 Sheets-Sheet 2 J3 I 27 :0 27 4o 4o Z? L/ I 3mm .I'Lzlg.8 PEG/MALI: a. MELLER R. B. MELLER April 24, 1951 INTERLOCKING CORNER CONSTRUCTION FOR CONTAINERS 9 Sheets-Sheet 5 Filed Aug. 14, 1945 5 B 3 i v r w 7 7 2 7 2 2 5 2 V\ v, Q. n w, n y. L I IILInII LI III a u n W \H a fl /N 0.U/ 7 V 9 m m 2 REGINALD B. MELLER April 24, 1951 R. B. MELLER 2,550,532

INTERLOCKING CORNER CONSTRUCTION FOR CONTAINERS Filed Aug. 14, 1945 9 Sheets-Sheet 4 REGINALD B. MEL-LE? IYNTERLOCKING CORNER CONSTRUCTION FOB CONTAINERS Filed Aug. 14, 1945 April 24, 1951 R. B. MELLER 9 Sheets-Sheet 5 llllllrl I l mldll April 1951 R. B. MELLER 2,550,582

INTERLOCKING CORNER CONSTRUCTION FOR CONTAINERS Filed Aug. 14, 1945 9 Sheets-Sheet 6 m z/vroz Eta/Amp 45 MFA/.5?

Arm/awn April 24,1951 R. B. MELLER 2,550,582

INTERLOCKING CORNER CONSTRUCTION FOR CONTAINERS Filed Aug. 14, 1945 9 Sheets-Sheet '7 Ap 24, 1951 R. B. MELLER 2,550,582

IN TERLOCKING CORNER CONSTRUCTION FOR CONTAINERS Filed Aug. 14, 1945 9 Sheets-Sheet 8 FIE FIEIEEINVENTOR.

' fEG/A/A'J fi, M62158 zw d.

April 24, 1951 R. B. MELLER 5 5 INTERLOCKING CORNER CONSTRUCTION FOR CONTAINERS Filed Aug. 14, 1945 9 Sheets-Sheet 9 IN V EN TOR.

F'I l5 :3 :El Kim/v4.40 5, Mame ATTOE/VE Y I Patented Apr. 24, i951 INTER/LOCKING CORNER CONSTRUCTIO FOR CONTAINERS Reginald B. Mell er, Oakland, Calif., assignor to Bemiss-Jason Company,'a corporation of California Application August 14, 1945,'Seri al No. 610,819

. '1 This invention-relates to an improved container and moreparticularly to one formedfrom creasable sheet material having a certain degree of stiffness and resiliency suchas is found in some types of cardboard, thin .sheetmetal, flexible plastic sheet material and the like.

In'my Patent No. 2,366,419 issued January 2, 1945, I have disclosed a .container made of the aforementioned materials and wherein each corner was formed and locked by a cut in one corner element engaging .a cut in another corner element in a line-to-line engagement instead of the hook or point-to-point engagement characteristic of prior containers. As will appear upon a detailedconsideration of that patent, one of thecuts was provided by cutting inwardly from the edge ofa corner element a sufficient distance to provide the requisite length of line contact with the cut in the other corner element upon subsequent assembly. While this was quite satisfactory, I have now been able to improve upon the construction in the following particulars:

. First, the construction of the container, in accordance. with this invention, is such that I am able to use a creasable sheet material of less stiff.- ness and strength than is required in the construction of my patent and still provide a satisfactory container.

Second,"I provide a container construction in which the rigidity of each corner is improved,

any v.tendencyof the sidewalls to spread away from theend walls being obviated :to a greater degree than has been achieved heretofore. *1 Third, in place of cutting the sidewall element, Iform a slot therein, thus preserving the strength of the wall.

."Fourth, the element interlocked with the sidewall element is available for and engages the third element forming the corner, thus improving the strength of the corner and enabling empty.

or filled containers to be stacked without the side or end elements spreading away from one.

tremely troublesome, expensive and requires considerable care and accuracy if the blanks are not 7 Claims. ('01. 229-35) to be injured. This is particularly so if the blanks areto be assembled by machine.

Sixth, a corner construction is provided which is relatively vapor tight and which, in addition,

is suited to sealing as by application of heat to the surfaces defining the corner if these are coated or impregnated with a heat sealing material.

Seventh. a corner construction in which one element is easily and quickly threaded through a cooperatively adjacent element, to lock the two together. Ease and quickness of threading is important particularly if the corner is to be machine assembled; the corner of this invention is peculiarly and particularly suited to such assembly.

The invention includes all of the foregoing ob jects and, in addition, others which will appear hereinafter.

In the drawings accompanying and forming a part hereof,

Figure 1 is a plan view of a blank from which my improved container is formed.

Figure 2 is an outside view in perspective of a corner of my improved container.

Figure 3 is an inside view in perspective of the same corner.

Figure 4 is a fragmentary view. illustrating the construction and relation between certain of the elements.

Figure 5 is 'a plan view of a blank illustrating another form of my improved container.

Figure 6 is an outside view in perspective of a corner of the container formed from the blanks shown in Figure 5, while Figure -'7 is an inside view in perspective of'the same corner.

Figure 8 is a fragmentary plan view of a corner element illustrating the construction andrelation between the several components.

"Figure 9 is a plan view of a modified form of blank from which an improved container of this invention'can be formed.

Figure 10 is an outside view in perspective of a corner formed of the modified improved container.

"Figure 11 is an inside view in perspective of the same corner."

Figure 12 is a fragmentary plan view of another modified form illustrating one corner construction of the present invention.

Figure 13 is a plan View of a portion of a corner of another modified form of container.

Figure 14 illustrates the container shown in partial plan viewin Figure 13 assembled partially,

while Figure 15 shows the container completely 55 assembled.

Figure 16 is a plan view of another modified form of blank from which an improved container can be formed.

Figure 17 is an outside View in perspective of a corner of the blank in Figure 16, while Figure 18 is an inside perspective view of the same corner.

Figurej19 is anenlarged pla'n view'of a'corner of the blank in Figure 16.

Figure 20 is a plan view of another modified form of blank from which an improved container can be formed.

Figure 21 is an outside View in perspective of a corner of the blank in Figure 16, while Figure 22 is an inside perspective view -ofthe same COIIIGI'.

Figure 23 is an enlarged plan view of a corner of the blank in Figure 16. p,

Figure 24 is a plan view of a corner of a box blank which can be assembled to include "a top closure.

"Figure 25 is side'elev'ation of thebox blank of Figure 24 with the box assembled.

Figure 26 is a side elevation of thebox shown in Figure 25, this view being taken with a'position "of the boxcut "away "and looking 'at the interior of the box.

Figure 27 'is"a'p1anvieW-0f a box blank which can be readily assembled by machine to provide acontainer including top orcover portions.

' Figure 28is-"a 'fragmentaryside view of the assembled corner.

Figure 29'is'a'fragmentaryview of an assembled corner of Figure 28takeh inside the container.

"Figure 30is a'plan'view of a box blank which can be'readilyas'sembled by machine to provide a container including top or cover portions.

Figure '31 isa fragmentary end view of the assembled container.

Figure 32 is a' view of theend of the container shown in Figure 31 but taken from inside the container.

Figure 33 is a 'p'lan view of a'modified corner blank construction while Figure "34 is a fragmentary side elevation' 'ofthe"assembled corner.

In its preferred idrm, referring particularly to Figures 1 through 4, my invention provides for a container a'blank"'5 of substantially rectangular form'an'd scored'as" at Iii, 22and3il, to define a bottom section I and side and end wall sections 9 and lL're'sp'ectively. Extending from each end of an end .wall section I I, and preferably integral therewith, is a wing I3 separated from theadjacent 'sidewallsection'il by outfit. ihe freeedge I'of wing l3 terminatespreferablyin alignment with the free longitudinal edge I I of the adjacent sidewall section 9. It will be noted that the container blank is'rectangular in outline and that no out out portions are'providcd. The blank can therefore be out continuously from a continuous stripwithout any wastage whatsoever except the material out 01f as trim along each end wall section H, edges I5 and I! on one blank'being common to the adjacent'blank and being formed on the two adjacent blanks by one cut.

Each side wall sectiOn'Q; in proximity to each end thereof, is provided with a cut I 9, this out being made at 'somedistance in from the free longitudinal edge I! of the side and'in a direction preferably at arr-acute angle to the cut 40. Each sidewall section 9 also includes a cut 20 extending parallel to cut 40 and with cut 19 forming a slot opening toward the wing I3.

Each end wall wing I3 is suitably cut to be received cooperatively in the slot provided by cuts I9 and 20 in the adjacent sidewall when the-side 4 and end walls are formed into corner forming position as in Figures 2 and 3, usually at 90 to one another. To ensure that cut 21 and cut 19 inter-engage in the desired line-to-line contact, out 2? is formed in a direction normal to that of cut it and at such a distance from the center or apex 23 of the corner that the inner "edge of cut 2? falls inside of the end of cut I9. This can be ensured by having cut 2! and cut I 9 terminate "upon a circle swung about center 23, the cuts then terminating at the same radial distance from center 23 about which the end wall and sidewall swing into position. Cut I9 can extend inwardlya 'greaterdistance if desired.

'O'ne can utilize the construction so far defined in which case the'corner will look only due to the line-to-line engagement of cuts l9 and 21. However, by providing cut 29 in each wing l3 at the same radial distance from center 23 as cut 20, an additional interlocking engagement is provided, cut 29 'also being normal to cut-122.

The blank is now in condition to be'assembled into a container. In'forming'the box, thesidewall and endwalksectionsil andv II of the blank are'creased along. the 'scorelines -Ill,-.22'and 3!] of the blank to iormthe respective sidewalls and end 'walls, and either simultaneously with $01 following such creasing, the sidewalls f9 are pressed inwardly'atth'esame time that the 'end wall sections II are moved inwardly on the bottom l. The wings l3 are also moved about crease lines 22, the slots formedby'cuts 'I9an'd 29 being opened and locking tab'orztongue 33 moved into position to lock the end walls, the wings, the sides, and the'botto'm inpositionas appears in Figures'2iand3. ReferringtozFigure 3, it-is to be noted that the tab portion'33of the wing '23 which "extends into cuts l9uand 20 engages bottom 'I and so provides a support for the Wing directly upon the bottom of'the' container while the entire end of the sidewallabuts the end wall. This'is of material advantagepena'bling a lighter stock 01" one having'rless stiffness to be employed at the'same time that-a'more rugged and rigid container'is provided.

I have previously ind'icated in connection with the structureshown in"Figures 1 through 4- that one or two locks could be provided between the several elements making up eachcorner of the container. 111- the modification shown in Figures 5-8, two locks are also provided. However; in this case, instead of cut29' being provided normal to cut 48, it ispositionedat an angle theretoywhile out 20 "isformed "with-"an angularcut" 52': at its lower end, the two *cuts being *designated as 5| and 52. As appears in Figure 8, out 5I.:is normal to cut-52 and is formed with its zinnerend at the same radial distanceiromwcenter'23 of the corner as the inner end' of cut 5i socutSI inter-engages cut/52. By forming the twocuts' atian'angle to cut 49, the final corner is possessedofigre'ater rigidity.

While I have disclosed the preferred embodiment ofmy invention in detail, I'donot wish to be limited in my protectionto such details as-the specific embodiments-disclosedfor these are susceptible to change and modification without de-' parting from the principles and spiritfof -my invention. For example, a container may beconstructed withthe end walls-'ofthesame height as the sidewalls byforeshortening the end walls or by increasing the height of the sidewalls. The modifications or -embodiments shown-'are particularly suited to thedisplay ofarticles such as doughnuts; and to thewrapping of1these-ir1--the usual cellophane or waxpaper heatsealing and wrapping machines; Also, in place of providin an open container, as the form illustrated provides, additional elements can be included to provide a top or closure means so that ,a :box is provided. Also, in case the corner to be formed is one in which theseveral elements are to be at an angle greater or less than 90, then the angular. value to be employed in providing cuts 21 -I'9, 29-,-20 and til- 52m the proper relationship can be suitably altered.

To facilitate assembly ofany of the forms depicted, I have illustrated in Figures 9-12. a form of blank in which only a single lock is provided,

the cut 29 being totally omitted and the lock being by reason of the engagement, in a face-to: face contact, of the cuts 21 and I9. These blanks include the provision of additional cuts 5|. Each of these cuts is preferably offset slightly from the fold lines It) so that edge 32, defining one side of 'cut40 on wing IE, will seat upon the material between cut 5! and the fold line I0. In the form of device shown in Figure 9, the cuts 5I' are shown as continuing in the same direction as cut [9 while in Figure 12 the cuts are shown as extending in a direction opposite to cut l9.

The form (Figure 9) in which the cut extends in the same direction as cut I9 is preferred, inasmuch as it simplifies manufacture and enables the tongue so provided to spring out of the way and permit the entering portion. of wing IE to thread in easily. Also, when wing portions 33 is. threaded into position, as appears in Figure 11, it tends to spread out away from sidewall 9, thus locking the corner very securely. The cut 51 enables the structure to be assembled readily by machine, inasmuch as it facilitates the threading of wing [5 into and through cuts l9 and 20,

particularly into the final assembly position.

Machine assembly of the carton or box is a feature of the blank. shown in Figures 16-23. In this form of the invention the slot 81 formed in each sidewall section 9 is arcuate in form as appears in the drawing. The slot 8| includes a portion 82 at 90 to cut 21 and positioned with respect to corner 23 so as to intersect cut 21 and when the corner is assembled. The two, that is, slotportion B2 and cut 21, are preferably of the same length so that an edge-to-edge contact exists when the corner is assembled although this is not essential solong as portion 82 will pass locking tab 33. Beyond portion 32 the slot extends tab 33 to be inserted and cut 21 will engage and look even though the angular measure is less than 90 for the cut will engage cut l9 orslot 82 if unlocking movement of the end should occur.

In Figures 13, 14 and 15, I have depicted one form of the device'which is particularly suited to the packaging of loose, bulk products such as potato chips and the like, or to assembly ofthe package about the product. As is knowmpotato chips are quite fragile yet, because of their irregular size and shape, they are difiicult to pack-- age, and heretofore they have never successfully 7 been placed in a carton. Their packaging in bags is undesirable because of the difficulty attendant upon the operation and because the bag offers so little protection. Referring to Figure 13, I have ture. In operation, the end 6| is first made up,

wing 62 being threaded into cuts 66, 61 and 68 until cut engages with cut 66. The wing I5 is then threaded through cuts I9, 20 and 5| so that the device, in side elevation, appears as in Figure 14. If, in this position, a previously weighed mass of potato chips are discharged into the container and-the latter is then vibrated, the potato chips rearrange themselves and shake down into a position entirely in the carton. If the ends H are then forced in until finally cut 21 engages with cut l9, each of the ends is locked in position with the product in the package. The package can thenabe wrapped with wax paper, or cellophane or the like, or, if desired, the extent of end section 6| can be such that a complete closure is provided for the top of the package.

In addition to the packaging of potato chips, the carton is readily suited to the packaging of numerous other products in addition to these. Further, it is believed to be obviousthat the package can be formed about a previously positioned product. For example, the container is readily formed about a previously positioned mass of butter, weighed out and formed into suitable shape.

By reason of the extensive surfaces in engagement between wing l3 and the sidewall 3, as appears in Figures 2 and 3, for example, the container of the present invention is particularly suited to the use of a heat sealing composition, the areas being so extensive that sufficient of this composition can be provided to secure a relacut 21 and the slot. The tongue provides sufii- 23 that the two interlock simultaneously with the edge-to-edge locking of cuts 21 and slot 82. The double lock makesthe corner more secure and capable of resisting unlocking.

Cuts 21 and 19 or cut 21 and slot portion 82 need not be exactly at 90 for the slot enables the tively great degree of adherence between the abutted surfaces. In addition, the container of the present invention is particularly suited to manufacture of a structure in which the end walls extend above for a considerable distance the sidewalls 9, in this position the end walls having sufficient strength to support additional cartons powing edge in the openingbecomes compressed tositioned upon them whereby they can be stacked waidthetase of theopnifig theedge 'is' fored when -Sincet'wo thickhesses'bf hoard hfa 7 1ace'd-o'i' 'threaded "at the baseoffth nm by the" movement of the wing edge, the ins 'tion of a cut-ate determined top oiht ii to'prouuce-asquarebut less'if desire an ngular-form) the inhefent =i-esi11ence of the material of Whicht he container is fashioned terids to for'ce the two iiiterl'aed' s'ti-rfaces ihtoa posi- 'tion 'in which theyere in a eomn'ion plan i.- the bottom face of thetah a liiis in" the p ane of thetop face of the "side walrandthe top face of thwingcut aligns with the bottor'niace; sa resulti nioveme'nt is arrestedwith'all four edges in a fafee te face engagement; A v The exte'ns'iohoi the outer wall'operiing at its base aria'beyona the len th; of the'e'dgeof the wingtab'is coordinated with the caliper thickness of the mate'rial and the desired positiveness of theengaginent. The extension of the lower leg of the wall opening can be longer and extend straight or curve up or down.

The position of the Wall opening "can be substantially tangent to any position of the-"tab out, "related to the position and based the Wingtab' edge, so long as the opening andtab cut actuate from a common pivot point-and are.

A secondary lock can be provided, as I have indicated, at the base of the opposingleg of the Wall opening under the same conditions buttevers'ed with respect to the primary lock. The secondary lock can become, in fact, a primary look when style and conditions warrant or perm-it.

Theapp=1ication of'h it to' r'iiatefiai coated with a heat s'ealing' material can produce additional sealing over and beyond theph'y si'cal' look action. The strength of the-lock "in-resisting opening increases inproportion to that fioint whereat the materialat the base offthe out on the wing tab willtear. The application ofheat sealing materials "enables the strength of the" corner" lockto be increased to that'of the entire" corner.

The containers can be partially-set up But not locked. In this position they can reeeit-e solid. bloelis of nfateiial like butter or fia-kv material like potato chips. 'The container elements can'- then be' rho-v'e'd to a lockedposition atom the packaged products.

A blank construction, enabling this mode of packaging to be emhloyed; is s'hownih; Fiure 24. In addition to the previously described blank elements; a top portion 9i is'po'sit'i'oned onen'd H from which it issiiar'ated h'y crease line 92. The top portion can extend mayhem crease line 92 for any desired distance; in any case, it should be sufficient to provide a cover of desired extent, usually in conjunction with alike 'ele ment at the other end of the blank. -A --s'eoon"d wing tab 93 is provided on the side of the we portion or' cover 9 i; from whiehit iss'eparateuty' a crease line 95. The height of the second wing tab" is such that it canbe-fit'ted inov'ef'th first wing tab [3i 'the' latter'b'e ing out 'away' to 'iierhiit' this, to engage out 95 w-ithfslot'porti'on 82'. Cut; 94 is substantially parallel to -slot po tion '82 and is provided in such'a position that vi hent he thing tabs are folded in on their or'ea-se lines 2:2 am 55; and the end" and top are riiove'd about crease lines- 30 and 92, cut-9Q is' 'in no's'i'tion to engage" and lock the top. This threading enab1es=- the blank' to be partially assembled with the top" at nto q n iifi o 3 o HWB T DI 9,? 1 5s? an the jl 'h'se jof "the container and the latte n??? hi m p p. i si t a t at the e lr l. n a leni'ents'he locked iiipositibn, particu i ly h i it e em' m Whe n-e 19.- ph'a e1 oi; the-like; I The frictional engagement of b :i; fi ,01 w lir t w h m v a m it ng fii J T si ilf r e'to Fs s z'l ha hown me e 'Wh i ith b nm-fv ed byi it e a one" m'or is s t i e aliifdfil isahsentarid frictional ngagemnt is ene 'ideqi g ,l e. a it ufi' i f' per eu a i i e M9; jt fe sb' qi i Feb 23 u at; n re time was It; which slips' in behindisidei wane while the ter-Ward hortionof the tah threads bete'eir ta 1-3 anethe end alr 'asfappears in Figure 29; The forinf'of containershown'in ths'e viewsin eludes a-t least one side wa1l 9 cut away 'as'at an; to dishlay'the p'aekaiged goods. A Top' pfortion gi at eachend ofthe container protects thegoods and permits the p ao ke'd containers to he st a ':l-ted Of course,- one or m re Queen be providdjin-ta3b is to engag ecutsf a2 and 81 if theiiiter-thr'eaded tongue lik' 1 locking is desired in'addition' tdthe frictional tetfntion: o i It is' necessary that the corner loekjbe formed between the bottoiiL- side and end Walls an d ini Figures 3'0 3"2 I' have shotv'na mamasnon wherein slot 8| is formed in the end ten and the ends of side wan 9-ar fa sh ionecfto be joined with the si t es" I have eesefit a'm 6onneetie'n withni'gure -;i9'. In this eas locking cuts are omitted; th can be included if desired.

The foi'fiibf 's lt -fl l oa'li \ffiiiidtti s l li t'th hartieular container desired, the product and, the means utilized for a'ssefiub1y. Various-forms have 'eenshow the drawing; arfd' that aefii'cte" Figures 331 and is par ti'ct'fia'ily suited for n threading er the looking tab into" engagement, both fr'itional engagement and locking engageme ts cut 5"? andcut 82.

This" is a conti-nu'a -1n-1Ja' it"of applihation Serial Number -5'79,7-27,- filed Febriiary 25, 1945 now Patent-No; 2528,9001

1. In a folding to; hav'm a t'ottojm; aside wall hingedlytonnepted to 'said'bottoni along a bottom fold line, the sidetjall having side fd forming an angl'e' of not=1ssthahf90 deg-fees With said ldottoih fold line, ane'rfctvfafil h'iiiedly eon: hected to "sa id lobttofii alone an e d fold line meefihe thelooiitqiiiffoldline at the box bottom corner, a top Wall hin'gedly cornieot'd to" said wall" along a tenfold line; amend'tvali side flap hihgedly coni'iecte'd' to' the side of said end Wall along a side foldlin'e meetihg'said top fold linea t'the-bo2' top c'o'rnen and" artop' Wall side flap hingedly-connectedto the side of said top Wall, said side flaps being foldable upon each other and'upon said side wall; an improvedinterlock forsaidend," top and side walls,-;saidimproved interlock -being iornied Joy an internal cutof bent outline in said side Wall forming an internal tongue in said sidewall pointingtowards the end Wall when the Walls arein box' f oiflning position and a out edge onea'ch of th'side e515; bordering external tone'ufsf on said fi ps; relative position of s'aid side wall a flaps, being such that in thepo'sition' in which d side' edge said side-flaps'l'ieontop of eachother and of said side wall and underlie said tongue, portions of said out edges on said external tongues being in line-to-line, as distinguished from point-topoint coincidence with out edges formed by said internal cut permitting an edge portion oneach of the flaps to engage coinciding edge portions of said internal out, the saidedges being urged into, and maintained in, engagement by inherent stiffness of the stock ofthe said. tongue, the external tongues on said end wall side flap and on said topwall side flap being shorter, measured from said. bottom corner and said top corner,

respectivelythan the distance from the respective corners of the end of the internal cut farthest from the bottom fold line.

2. In a folding box having a bottom, a side wall hingedly connected to said bottom along a bottom fold line, the side wall having a side edge formingsan angle of not less than 90 degrees with said bottom fold line, an end wall hingedly connected to said bottom along an end fold line meeting the bottom fold line at the box bottom corner, a top wall hingedly connected to said end wall along a top fold line, an end wall side flap hingedly connected to the side of said end wall along'a side fold line meeting said top fold line at the box top corner, and a top wall side flap hingedly connected to the side of said top wall, said side flaps being foldable upon each other and'upon said sidewall; an improved interlock for said end, top andside walls, said improved interlock being formed by an internal cut'of bent outline in said side wall forming an internal tongue in said side wall pointing towards the end wall when the walls are in box forming position, and cuts in each of said side flaps extending into the side flaps from the outer border of the side flaps, said last named cuts forming external tongues on said side flaps, the relative position of said side Wall and flaps being such that in the position in which said side edge abuts said end wall in edgeto-surface position said side flaps lie on top of each other and of said side wall and underlie said tongue, portions of said out edges on said external 1 tongues being in line-to-line, as distinguished from point-to-point coincidence with cut edges formed by said internal cut permitting an edge portion on each of the flaps to engage coinciding edge portions of said internal cut, the said edges being urged into, and maintained in, engagement by inherent stiffness of the stock of the said tongue, the external tongues on said end wall side flap and on said top wall side flap being shorter, measured from said bottom corner and said top-corner, respectively, than the distance from the respective corners of 'theend of the internalc'ut farthest from-the bottom fold line.

4 3. In a folding box having a bottom, a side wall hingedly connected to said bottom along a bottom fold line, the side wall having a side edge forming an angle of not less than 90 degrees with said bottom fold line, an end wall'hingedly connected tosaid bottom along an end 'fold line meeting the bottom fold line at the box bottom corner, a top wall hingely connected to said end wall along a top fold line, and a wing flap hingedly connected to the side of said top-wall, alonga side fold line meeting said top fold line at the box top corner, said flap being foldable upon said side wall; an improved interlock for said end, top, and side walls, said improved interlock being formed by an internal cut of bent outlinein said side wall forming an internal tongue in said side wall pointing towards the end wall when'the walls are in box forming position,

and a cut in said wing flap forming an external tongue on said wing flap, the said wing flap being insertable through said internal cut s o as to overlie said side wall to either side of said tongue and to underlie said tongue, a cut edge on said external tongue being in line-to-line, as distinguished from point-to-point coincidence with a portion of the cut edge formed by said internal cut permitting an edge portion of the flap to engage a coinciding edge portion of the internal cutwhen said end wall is moved into a'position edge-tosurface position, the said edges being urged into, and maintained in, engagement by said tongue by the inherent stiffness of the stock of the said tongue, the external tongue measured from the box bottom corner being shorter than the distance from the corner of the endof the internal cut farthest from the bottom fold line.

4. Ina foldingbox having a bottom, a side wall hingedly connected to said bottom along a bottom fold line, the side wall having a side edge forming an angle of not less than degrees with said line, an end wall hingedly connected to said bottom along an end fold line, meeting the bottom fold line at the box bottom corner, a top wall hingedly connected to said end wall along a top fold line, an end wall side flap hingedly connected to the side of said end walLand a top wall side flap hingedly connected to the side of said top Wall, said side flaps being foldable upon each other and upon said side wall; an improvedinterlock for said end, top and side walls, said improved interlock being formed by an internal cut of bent outline in said side wall forming an internal. tongue in said side wall pointing toward the end wall when the walls 'are-in box' forming position and a cut edge on one of said side'flaps bordering an external tongue on said side flap, said out edge coinciding in interlocking position with a portion of said internal cut-in line-to-l'ine as distinguished from point-to-point, coincidence, the relative position of said side wall and flaps being such that in the position in which said side edge abuts said end wall in edge-to-surface position said side flaps lie on top of, each other and of said side wall and underlie said tongue, permitting an edge portion of said'fiap to en'- gage the coinciding edge portion of said internal cut, said edges being urged into and maintained in'engagement by the inherent stifiness'of the stock of the said tongue, the external tongue measured from the .box' bottom corner. being shorter than the distance from the; corner of the end of the internal cut farthest fromthe bottomfoldline. jy 5-. An improved glueless corner" construction for folding boxes for assembling, in corner forme ingv relationship, a main panel, two wall panels hinged to the main "panel along fold linesform ing, an angle, and a flap hinged to one of the. wall panels along the side of said one wall panel,

the flap being foldable over the outside of the tongue in said other wall panel pointing towards 12:1 the-box corner: when the. panels .are. incorner forming position,wtheinternal tongue, upon flex.- ing with respect to .the (remainder: of said other wall panel, forming a I wedge shaped opening in-said etherwall. panelinto which said fiap may be swung, said. flap thavingi an. external cut extending into it from-an outer. edgersaid :external cut'coincidingrin interlockingposition with aortion of:- saidinternal cutin line-to line, as distinguished from point-to-point, coincidence, said external ,cu-t forming-an external tongue on -said fifih being oppositely directedto said internal tongue inthe. interlocking: position, said-external tongue being; bordered by-said externalcut. and at least one. outerred-ge 'of flap, thev distance from the endoirthe. external tongue to--the'-po-int of? intersection :ofsaid. fold linesbeing less than theadzistances from-said point of intersection. to the. end ot saidinternal= cut farthest. fromthe told line 'of said other panel, saidilap being:-par'.- tially insertable into said wedge-shaped opening hr h said: internalcutby a motion stewards said. main panel, the end of the internal cut nearest the fold line otr said other: panel": being spaced from the corner a distance. greater than the? lengthof. *thezbottom ed-ge of said flap,- so that ther-fiapv upon insertion into said-wedgeshaped opening underliessai-d internal tongue but overliessaidr other panel to either side 'ot said internal tonguewhereby. said external: tongue comes-to l-i-eunderneath-said:internal tongue-and both? tongues "resiliently "deflect said other; said internal cut: and said external 'cut providing cut edges: which; the position *in which said. side edge? abutsfsaid- "one wall panelin 1 edge-to-sur= face position; are in substantial coin'cidence permitti-ng" a coirrciding :edgeportion. of" one cut to engage an -edge:portion'of the-other cutin .edgeto-edge; asdistingnishedfrom pomt-to-point po-' sitiom. the; internal; tongue and theexternal tongue."v pointing: inroppositen directions an'dF-defleeting each othertd prodnce said edge 'to-edge engagement ofsaid coincidin cuts-whereby the inherent stiffness of" thestock-is utilized in as sisting theirespective edges automatically to. move into engagement-and remaimiir engaged posi- (ii-An: improved gluel'ess corner construction for -folding boxes as; set forth" in the? preceding claimi5 in which the endfoftheinternal out near estfthei-fol'ct line of said' onepanel'is spaced from saidifold liner 7. Animprovedglueliess corner constructi'onfor folding boxesf for assembling, incorner forming relationship, a main panel, tworwall panels hinged than thedistance from saidpoint of intersection to the end of said internal cut farthest from .the fold line of saidotherrpanel, said. external tongue being. bordered by-said two external cuts and by an outer edge of saidflap and ininterlocking'posi-tion being. oppositely directed to said internal tongue-,said flap: being. partially insertable. into said..wedge-shaped openingthrough said internal out by a. motionftowards said main panel, the end oiitherinternal cut nearestuthe fold .lineof said other-panelbeing spacediromthe corner a, dis.-

tance. :greater thantthe length. of. .the bottom edge ofesa-id .flap, so*-that the. flapupon insertion into saidwedge-shaped. opening underliessaid internal: tongue but overliesusaidother. panel to either :side a of said internal.-tongue,.whereby said external tongue also comeste lie-underneath said internal'tonguev and both; tongues resiliently defiecteach other, said internal cut and. said external: cutsprov-iding cut edgeswhich, inthe position iii-Which said; side edge abutssaid one Wall panel-L in edge-to-su-rface; position, are in substantial coincidence'permitting a. coinciding edge 'portionrof one cut "to engage an edge portion of the other: out; in edgee-to-edge as distinguished iromT-point-te-point position, the internal tongue and the: external-r-tongne pointinginoppositedirections and deflecting each other to. produce said edgeeto-edge eng-agement of said coinciding cuts, wherebythe inherent-stiffness" of the stockis utilized: in assistingthe. respective edges automatical-ly' tohmove into engagementand remain in engaged IJOSitiOH-L REGINALD B;

REFERENCES CFIIED" The following references areof record in the file. 'of 'this patent UNITED STATESPATENTS Numben Name Date 487,528. Hicks: Dec. 6; 1892 1,0795668/ Scott Nov. 25; 1913- 1,-554;,099:- Kolb'er Sept. 15, 1925 2,117 1 051: Stonecypher Aug. 29,: 1939' 2193 -925 l-liuyei Mar. 19; 1940 2,303,791- Rueckert Dec. 1,1942 2', 3.9'7.,4 8.4- Hedrick ApntZ, 1946 2,475,279 Dunning July 5; I949 FOREIGN PATENTS Number 1 Country: Date 468,015 Great Britain June 28, 1937 6,420 Great Britain of 1-906 

